1. Field of the Invention
The present invention relates to an electrification apparatus that is used for image forming apparatuses such as a copy machine, a printer, a facsimile, a multi-function machine of them and the like and an image forming apparatus that includes the electrification apparatus, more particularly, relates to an electrification apparatus that includes a support member which supports rotatably an electrification roller; and an image forming apparatus that includes the electrification apparatus.
2. Description of Related Art
Conventionally, in an image forming apparatuses that uses an electro-photographic system, an electrification apparatus is used to electrify a surface of a photoreceptor that is an image carrier. As the electrification apparatus, there known are: a corona electrification system which disposes a photoreceptor and a corona wire without contacting with each other and electrifies a surface of the photoreceptor by means of a corona discharge; and a contact electrification system which makes an electrification member such as an electrification roller and the like contact with the surface of the photoreceptor. However, in recent years, to reduce emission of ozone harmful to a human body, the contact electrification system, which has a less ozone emission amount, is used in many cases.
In such contact electrification system, in a case where the electrification roller is made to contact with the photoreceptor surface, in some cases foreign matter such a toner component, paper-sheet powder and the like adheres to the photoreceptor surface and moves to a surface of the electrification roller. If the foreign matter adheres to the electrification roller surface, the foreign matter causes defective electrification on the photoreceptor surface, which causes a serious influence on image quality of printed matter. To prevent such adhesion of the foreign matter to the electrification roller, conventionally, a cleaning member is pressurized to the electrification roller surface to sweep away the foreign matter that adheres to the electrification roller.
As a relating technology that removes the foreign matter on the electrification roller by means of the cleaning member, a technology is known, in which the cleaning member rotates with a linear velocity difference with respect to the electrification roller and reciprocates in a shaft direction of the electrification roller, thereby removing the foreign matter on the electrification roller.
However, in the above technology, a rotation shaft at an end portion of the electrification roller is held by a support member and there is a risk that the foreign matter such as the toner component, the paper-sheet powder and the like, which adheres to the photoreceptor surface, moves to the rotation shaft of the electrification roller.